In the winter months, the Arctic can experience 24-hour darkness. This can be disorienting and can affect your mood and energy levels. It’s important to bring plenty of artificial light sources such as headlamps and flashlights, and to take steps to combat Seasonal Affective Disorder (SAD) if necessary.
Conversely, if you plan to visit during the summer months the midnight sun will be out and shining nearly 24 hours every day! Not to worry, your cabin windows aboard your ship should keep the sunlight out during your resting times.